Science Spotlight

Station NEAH

Researcher: Tim Melbourne
Central Washington University

We have been focused on using real-time GPS measurements as a seismic network to pinpoint the size and location of large earthquakes within seconds.

View from NEAH overlooking the Pacific Ocean.

State: WA
Country: United States
Elevation: 459.9 m
Lat/Long:  48.2979 / -124.6249

Real-time Hazards Network

NEAH is part of the Pacific Northwest Geodetic Array (PANGA) real-time GPS hazards network. These hazards arise from earthquakes, volcanic eruptions, landslides, and coastal sea-level encroachment. In addition, PANGA GPS measurements are used to monitor man-made structures such as Seattle's sagging Alaska Way Viaduct, the 520 and I-90 floating bridges, and power-generation/drinking-supply dams throughout the Cascadia subduction zone, including the megadams along the Columbia River. GPS data are sent, or telemetered, in real-time back to Central Washington University (CWU), where they are processed in real-time to provide relative positioning of several mm resolution. Check out the Pacific Northwest Geodetic Array website for an overview of real-time GPS data, CWU's PANGA analysis activities, and data processing algorithms.

Figure 1. Earthquake sources in the Cascadia Subduction Zone. Both geologic evidence and historical records tell us that great earthquakes have occurred along the Cascadia Subduction Zone in the past. The largest earthquakes occur along the plate boundary, but dangerous earthquakes can also occur within both the downgoing plate (the Juan de Fuca plate) and the overriding plate (the North American plate).

Figure 3. Position of NEAH in a North America fixed reference frame. (For help interpreting the graphs, see the GPS Data page.)


Figure 2. NEAH is one of the hundreds of GPS sites that PANGA analyzes in real-time.

Spotlight Questions

  • If NEAH and the PANGA network detected a hazard occurring, whether earthquake, volcano, or structure collapse, how might this information be used to issue public warnings and guide emergency response?
  • How do the position changes for NEAH compare with nearby sites like ALBH and SC02?

Last modified: 2019-12-26  16:24:54  America/Denver  


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